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9 and conflicts. For example, often details for piping or database applications such as GIS add a level of intelli- electrical components can reside on one set of plan gence and detail to visual data. Visuals are now being sheets whereas the overall structural components for the used as vital planning tools instead of being a byproduct project reside on another sheet. Traditional methods of the design process. require constant referencing between those sheets. Three-dimensional interference detection improves this VISUALIZATION TOOLS process. Three-dimensional software applications can also automatically call out constraints for interference Key Factors in Determining What Tools Are Used detection or calculate sequencing processes. These visual tools assist the engineer in providing real-time The foundation of most computerized visualization tools is feedback on the design. This visual feedback tool greatly CADD data. CADD data can be derived from a variety of improves the quality and accuracy of the design. sources, such as survey data and field measurements. The · Funding and approval. To start the project planning data can be in 2-D or 3-D formats and can be simple or com- process, transportation agencies need to garner funding plex in design. Visual tools are used to enhance the CADD and support from state agencies, such as metropolitan design and to convey it in a variety of formats. Key factors planning organizations, and federal agencies, such as in deciding which visual tool to use include, but are not lim- FHWA. To assist in the funding process, visuals can be ited to, the following: used to help stakeholders and decision makers better understand the overall project goals and impacts. · Project goals. The most important factor in deciding · Public and stakeholder involvement. Used during the which visual tool to use is the project goals. Visuals public involvement process, visualization can play a need to have a purpose or else they do not serve a viable key role in acquiring support for the project; help citi- function. For example, if the project requires an inter- zens and stakeholders to make informed decisions; and active public outreach tool, web development tools foster enhanced relationships between transportation would be used instead of static photo-simulations. The agencies, stakeholders, and the public. Many projects right tool is needed for the right job. Visualization can be are ultimately decided by public acceptance. Because a critical to addressing conflicting objectives and/or values significant portion of public opinion is driven by a mis- between the agency, stakeholders, and the public. understanding of the project or by apprehension, it is · Project schedule. Another important factor in deciding which visual tool to use is the project schedule. The important to make sure the public understands the shorter the schedule, the less complex the visual tool design. Visualization improves understanding by better needs to be. However, having a short schedule does not conveying to the public complicated design issues (see mean that the visual tool will be less effective; it sim- Figure 7). This improved understanding often leads to ply implies that a different approach to conveying the project consensus and approval. design is required. · Homeland security. Homeland security is a relatively · Project budget. Once the project schedule and goals new use for visualization. It has been greatly accelerated have been determined, project budgets can be set. These since September 11, 2001. Visuals created for a project budgets are normally determined by the project man- can assist planners and security agencies in understand- ager. Currently, little to no formal information exists for ing security issues such as line-of-sight and structural project managers to access to help determine the visu- integrity. Three-dimensional visuals combined with alization portion of the overall project budget. Project managers rely on information obtained either from experienced transportation agency members or through consultants associated with the project. · In-house knowledge and experience. To successfully create visuals for a project, experienced visualization specialists are required. These specialists need to have a diverse array of knowledge about a variety of visual- ization tools. Project goals cannot be met unless the staff available has the correct skill set. Types of Visual Tools Hand Rendering FIGURE 7 Visual rendering of proposed site improvements at a Hand rendering is the oldest visual tool used within the trans- U.S. Coast Guard Border Crossing Facility in Buffalo, New York. portation design community. A hand rendering can be created
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10 by drawing or painting freehand images or tracing over existing CADD plans or elevations (see Figure 8). Although considered a "low-tech" visual solution, hand rending is still quite an effec- tive tool. Many engineers and architects would argue that the traditional method of hand rendering gives the drawing a human touch, whereas computerized rendering tends to look somewhat plastic. This argument has some validity, and only an experi- enced individual can produce electronic renderings that will sat- isfy the preferences of an experienced traditional renderer. Two-Dimensional Graphics Two-dimensional CADD data, graphics, and photography can be applied to a variety of visual applications (see Figure 9). Most meetings and public presentations rely on 2-D graphics FIGURE 9 2-D CADD file and associated rendering. to convey everything from demographics to budgets. This visual tool can be output to print mediums, web development, or electronic multimedia presentations. Two-dimensional graphic models may combine geometric models (also called consuming portions of creating visuals. Often, multiple ver- vector graphics), digital images (also known as raster graph- sions of the rendering are created until the proper "look" is ics), text to be typeset, mathematical functions, and more. achieved. The final product is a realistic rendering that can These components can be modified and manipulated by 2-D include environmental elements such as particles, lens flare, geometric transformations such as translation, rotation, and and subtle lighting and shading. scaling. Two-dimensional simulations or photo montages can be very efficient and effective on some projects. Photo-Simulation Once the 3-D rendering has been created, it can be incorporated Computer Renderings into an existing photograph using a photo-editing package (see Computer rendering can be used after the 3-D model has been Figure 11). The goal of the photo-simulation is to educate the completed. Once completed, the model is inserted into a ren- observer while at the same time creating a seamless composite, dering program, where it is assigned variables that assist in whereby the computer graphics blend into the picture. Photo- adding realism to the model. Elements such as color, texture, simulation can provide the realism that the general public and lighting, reflectivity, and shadow are defined within the the design industry expect to see in visuals. model. The rendering program then computes these elements and produces a realistic rendering (see Figure 10). Inserting these variables into a rendering program and creating realis- Computer Animation tic output takes an artistic eye and can be one of the most time- Computer animation is the art of creating moving images by using computers. It is a subfield of computer graphics and animation. Increasingly, computer animation renderings are FIGURE 8 Hand rendering; the oldest visual tool used within the transportation design community. FIGURE 10 Toll plaza rendering. (Courtesy : SUNY at Buffalo.)
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11 FIGURE 12 Computer animation of Virgin River Arch Bridge. (Courtesy : Utah DOT.) If the project requires 60 s of computer animation, then, based on the 5-minutes-per-frame calculation, it will take 9,000 min, or 150 h, to render all the frames necessary to pro- duce the animation: · 150 min to prepare each second of computer animation. · 60 s of computer animation required for the project. · 60 × 150 = 9,000 min to prepare computer animation. · 9,000/60 min = 150 h. Production houses, consulting firms, and some trans- portation agencies use render farms or network-distributed rendering to improve processing and production time. A render farm is a computer cluster that renders computer- generated imagery. The rendering of images is a highly par- allelizable activity because each frame can be calculated FIGURE 11 Photo-simulation of existing conditions (top) and proposed conditions (bottom). independently. The main communication between proces- sors is the upload of the initial models and textures and the download of the finished images. Network-distributed ren- dering is the process of aggregating the power of several created by means of 3-D computer graphics, although 2-D desktop computer workstations to collaboratively run a sin- computer graphics are still widely used. Sometimes the tar- gle computational task in a transparent and coherent way so get of the animation is the computer itself; sometimes the tar- that the workstations function as a single, centralized sys- get is another medium, such as film. tem. This form of rendering is used when a render farm is not practical or feasible. Instead of purchasing and main- Essentially, computer animation is a series of computer ren- taining a render farm, desktop workstations available on a derings that are strung together (see Figure 12). Time constraints network are used. Usually these workstations are accessed need to be considered when deciding to use computer anima- during the evening hours so as not to prohibit other uses of tion, because rendering can be a time-consuming process. The the workstations during the day. computer systems must generate all the renderings necessary to create an animation, and it takes 30 frames (that is, renderings) Overall, when using computer animation, careful consid- to generate 1 s of computer animation (see Figure 13). Thus, for eration needs to be given for the production schedule owing example, if it takes 5 min to generate one rendering, it will take to the amount of potential rendering time. 150 min to generate 1 s of computer animation: · 5 min to prepare each rendering. Real-Time Simulation · 30 renderings to create each second of computer anima- tion. Based on virtual reality, real-time simulation is a graphical · 5 × 30 = 150 min to prepare each second of animation. database technology that allows for interactive navigation
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12 FIGURE 13 Frame count needed to generate 1 s of computer animation. throughout a digital model. This visual database has the can be toggled on and off. This ability increases overall ability to foster rapid conceptual approvals, help identify understanding, which can translate into schedule and budget design flaws, and reduce development costs before the savings. The nature of this technology allows for quicker commencement of construction. This technology has been response times in implementing design changes. pioneered by the U.S. military for flight and combat simu- lation and is rapidly becoming a key tool for the urban Real-time simulation can be a key master planning tool. design and planning community. Cities such as Las Vegas, Because it is a database, it can be modified for years to come. Nevada, and Cerritos, California, are currently using the As changes occur to the project, the database can be updated. technology to help with planning and design issues (8). Additional features, such as a proposed building or roadway Although traditional visualization methods have been used conditions, can be incrementally added to the database. Ulti- as a presentation tool, real-time simulation streamlines the mately, the database can be expanded to contain large met- complex phases of planning and designing a project by inte- ropolitan areas. The technology can be used throughout the grating multiple sets of plans and elevations and allowing life of a master plan, providing greater communication and the viewer to see them simultaneously instead of one sheet concise understanding, which in turn will lead to quicker at a time. acceptance or approvals. Being a database itself, real-time simulation can be linked The strength of real-time simulation lies within its interac- to other databases, such as GIS applications, traffic simulation tivity. Designers will have the ability to view their concepts utilities, or facility management utilities. Without real-time interactively. Critical issues such as building aesthetics and simulation, these other databases are stand-alone and cannot line of sight, which are security issues, can be easily identified. be linked together. However, real-time simulation can view The general public can also obtain a greater understanding of these database formats simultaneously and allow the user to the study by viewing the proposed changes from many per- navigate interactively throughout the digital model, thereby spectives. Public outreach and support can be more effectively making the database "intelligent." By dynamically linking achieved. Other visualization tools for high-profile projects real-time simulation to other databases, decision makers will have often created additional misunderstanding because these have the ability to analyze various types of information. If the methods do not fully convey impacts in basic terms that the simulation is set up properly, it can interactively display tax average person can understand. With real-time simulation, base information, utility and building statistics, traffic simula- participants can interactively move around a site to see every tions, and more. angle and obtain greater understanding (see Figures 1417). Real-time simulation technology has the added ability to Real-time simulation is a unique planning tool that can interactively analyze multiple design options. Objects such produce greater levels of communication and understand- as proposed buildings, roadways, and underground utilities ing. Users of this technology need to be aware that, unlike
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13 FIGURE 16 One angle of a real-time 3-D simulation model of a FIGURE 14 One angle of a 3-D simulation model of a building. proposed public safety building. computer animation, real-time simulation cannot render elements, such as information-gathering forms and multiple light sources, shadows, or reflectivity. These capa- database-driven elements. bilities are currently available only with computer rendering · Project-based sites. These sites allow the project to or animation. They are commonly used to provide greater be managed from multiple and even remote locations realism to the computer model or when lighting or shadow by means of the Internet. Management tools such as studies are required for a project. Therefore, if the goal of project scheduling, e-mail, and file management can the project is to show any of these details visually, real-time all take place on the Internet. Various levels of secu- simulation should not be used. rity can be assigned to ensure data integrity and accu- racy. With one common site, data for the project can be located quickly. Past problems of multiple file ver- Web Development sions can also be eliminated by a common project- based website. The Internet has revolutionized how information is conveyed · Public outreach. These sites enable the general public and shared. The transportation design community has recog- to both access up-to-date project information and voice nized web development as an important part of the overall its opinions and concerns (see Figure 18). As the proj- project development process. Several categories of websites ect progresses, the website can be updated with such can be produced, including, but not limited to, the following: information as project milestones, present and future traffic impacts, alternative transportation solutions, · Promotional sites. These sites typically serve as an published meeting reports, and schedules. online brochure to help increase public awareness for pending, upcoming, or active projects. They are usually Multimedia Development static in content, but may involve some dynamic Multimedia systems support the interactive use of text, audio, still images, videos, and graphics. Each of these elements must FIGURE 15 One angle of a real-time 3-D simulation model of a FIGURE 17 One angle of a real-time 3-D simulation model of a proposed roadway. proposed building.
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14 FIGURE 18 Public outreach website. Place your mouse over the colored areas for more information. FIGURE 19 Multi-media graphic with "roll-over" capabilities. FIGURE 20 Scene from a video production that combines Roll-over capabilities allow the viewer to select an image within photo-simulation, 3D digital modeling and animation, and the graphic to see alternative images and text. computer-generated graphics.
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15 be converted in some way from analog form to digital form reach tool that can be shown multiple times and from most before they can be used in a computer application. Thus, the locations. Video productions can be aired on local cable distinction of multimedia is the convergence of previously access, and copies can be made available at various munic- diverse systems. Commonly, multimedia elements are con- ipal facilities in a variety of formats, including VHS, DVD, sidered applications that are executed from a CD-ROM. The CD-ROM, and Beta-SP. Video production is the art and ser- key advantage of this visual tool is its interactivity. The user vice of producing a finished video product to a customer's has the ability to navigate at will throughout the multimedia requirement. Videos can satisfy a wide range of demands, system, using such features as "roll-over" capabilities to from demonstrating safety features in dangerous environ- access alternative images, audio, or text (see Figure 19). ments to providing training. An example of a more everyday Examples of multimedia tools include self-paced tutorials, application is a television news article. Video producers take informative project pieces, and outreach tools for stakeholder an outline, produce a script, create storyboards, and begin or public involvement. production. This process often includes experts ranging from CADD staff to computer graphics technicians. The Video Production production is created, put on broadcast-quality tapes, edited, and presented in a draft or "guide" form. Sound tracks and Video production combines the visual tools of photo-simu- visual effects are then added, and the final video is pre- lation, 3-D digital modeling and animation, and computer- sented. With the increasing use of video in a wide range of generated graphics to create an informative depiction of a commercial and government functions, video production is project (see Figure 20). The final product is an effective out- a fast-growing industry.